Which statement best represents LeChatelier's Principle?
a. A system in equilibrium will always remain in equilibrium.
b. Only a change in equilibrium will affect the equilibrium of a reaction.
c. When a change is made to a system in equilibrium, equilibrium can never be restored.
d. A system in equilibrium will respond to a change by moving in the direction that reduces the change as it returns to equilibrium.
e. A system in equilibrium will not be affected by a change in concentration.
Answer: d. A system in equilibrium will respond to a change by moving in the direction that reduces the change as it returns to equilibrium.